This invention relates generally to vibratory rollers used in leveling paved or unpaved ground surfaces and more particularly, to a vibratory mechanism for use therein.
In the past, vibratory rollers have been provided with vibrators which include a motor-driven shaft carrying an eccentric mass. Usually, the eccentric mass is adjustable between a plurality of discrete radial positions in order to vary the amplitude of vibration. Generally, the vibratory mechanism is started with the mass disposed in the same position relative to the shaft which is occupied at earlier shut-down. As a result, the motor of the vibratory mechanism must be large to be capable of handling the potentially great start-up loads, especially in cases where the mass is situated in the high-amplitude position at start-up.
It is, therefore, an object of the present invention to reduce the required size of the motor for the vibratory mechanism.
It is another object of the invention to assure that minimal start-up loads are imposed by the eccentric mass.
It is a further object of the invention to assure that the mass is automatically positioned and locked in a low-amplitude setting when the vibratory mechanism is shut-down.
It is a further object of the invention that the vibratory shaft can be rotated in either direction at any amplitude setting without affecting the amplitude thereby allowing to reverse rotation of the eccentric weight. Thus rotation of the eccentric weight may be made opposite to that of drum for better compaction.